1906421 has 8 divisors (see below), whose sum is σ = 2109888. Its totient is φ = 1708000.

The previous prime is 1906417. The next prime is 1906439. The reversal of 1906421 is 1246091.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1906421 - 2² = 1906417 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1906481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 440 + ... + 2001.

It is an arithmetic number, because the mean of its divisors is an integer number (263736).

2^1906421 is an apocalyptic number.

1906421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1906421 is a deficient number, since it is larger than the sum of its proper divisors (203467).

1906421 is a wasteful number, since it uses less digits than its factorization.

1906421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2523.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1906421 is about 1380.7320522100. The cubic root of 1906421 is about 123.9955990460.

The spelling of 1906421 in words is "one million, nine hundred six thousand, four hundred twenty-one".